Katz 2004.

Methods	Double‐blinded, placebo/sham‐controlled, randomized clinical trial Sequence generation by computer‐generated random numbers Follow‐up: 6 months
Participants	Participants: 152 adults in a university setting in Toronto, Canada Operation: laparotomy for major gynaecological surgery 3 groups, size: 49/56/47 Age: 44 years (SD ± 8.9), 47 (SD ± 10.6), 44 (SD ± 9.6) Men/women: women only
Interventions	Group 1 (preincisional epidural): epidural catheter at L2/3/4 tested, GA, preincision: lidocaine (2% with epinephrine (1:200,000), 12 mL plus 0.8 mL for each 2.5cm (1 inch) of height above 152cm (60 inch), plus 4 µg/kg fentanyl), 40 min after incision epidural normal saline (12 mL), post‐op morphine PCA (loading dose 4 mg, then bolus 1.0‐1.5 mg, lockout time 5 min, max 40 mg in 4 h, no basal rate) Group 2 (postincision epidural): epidural catheter at L2/3/4 tested, GA, preincision: epidural normal saline (12 mL), 40 min after incision: lidocaine (2% with epinephrine (1:200,000), 12 mL plus 0.8 mL for each inch of height above 60 inch, plus 4 µg/kg fentanyl), post‐op morphine PCA (loading dose 4 mg, then bolus 1.0‐1.5 mg, lockout time 5 min, max 40 mg in 4 h, no basal rate) Group 3 (sham epidural): sham epidural catheter at L2/3/4 tested, GA (fentanyl 1 µg/kg), preincision: epidural normal saline (12 mL), 40 min after incision epidural normal saline (12 mL), post‐op morphine PCA (loading dose 4 mg, then bolus 1.0‐1.5 mg, lockout time 5 min, max 40 mg in 4 h, no basal rate) Adjuvants: none Immediate post‐op pain control: not significant
Outcomes	Dichotomous: pain at 6 months, analgesic consumption at 6 months Continuous: Pain Disability Index, Mental Health Inventory‐18 and McGill Pain Questionnaire at 6 months Secondary: allodynia/hyperalgesia
Notes	Funding sources: supported by grants from the National Institutes of Health and the Canadian Institutes of Health. Conflicts of interest: conflicts of interest were not reported.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: “a randomization schedule was computer generated by a biostatistician.”
Allocation concealment (selection bias)	Low risk	Quote: "an opaque envelope containing the patient number and group assignment was prepared, sealed, and numbered for each patient by the hospital pharmacist, not involved in the study otherwise...All patients and personnel involved in patient management and data collection were unaware of the group to which the patient had been allocated. The anesthesiologist in charge of the case was aware of group allocation for control group patients and was not involved in postoperative management or data collection."
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "all patients and personnel involved in patient management and data collection were unaware of the group to which the patient had been allocated. The anaesthesiologist in charge of the case was aware of group allocation for control group patients and was not involved in postoperative management or data collection." but the anaesthesiologist in charge of the case was aware of group allocation for control group participants.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "neither the person conducting the interview nor the patient was aware of the group to which the patient had been assigned," "personnel involved in ... data collection were unaware of the group to which the patient had been allocated."
Incomplete outcome data (attrition bias) All outcomes	High risk	Quote: "both an intention to treat analysis and a protocol‐compliant analysis were performed." "There was no appreciable difference in the results of the intention‐to‐treat analyses and the protocol compliant analyses. Data and results of significance tests reported below are therefore based on the intention to treat analyses." But ITT was only done for early outcomes, not for questionnaire data at 6 months, when significant attrition occurred.
Selective reporting (reporting bias)	Unclear risk	Primary outcomes fully reported on
Null bias	Low risk	Quote: "preincisional administration of epidural lidocaine and fentanyl was associated with a significantly lower rate of morphine use, lower cumulative morphine consumption, and reduced hyperalgesia compared with a sham epidural condition"